New problem with the .45-70 Buffalo Classic

I finally have the scope adjusted for POI=POA at 100 yards for the .45-70 H&R 1871 Buffalo Classic I bought last summer.

But I have a new problem that popped up while I was getting the scope adjusted.

I cleaned the primer pockets on all 306 pieces of brass using an RCBS Primer Pocket Brush, chucked up in a drill clamped down to a platform, with the speed dialed back to a fairly slow speed. Plenty fast for what I was needing it to do, but nowhere near the several hundred RPM speed it was capable of. All of the primer pockets were nice and clean, no crud buildup in the bottoms.

I seated Winchester LR primers in a hundred or so cases using an old-style Lee hand priming tool (all the boolits I had available). Over the course of three outings, two to four weeks apart, I would load a round in the chamber, cock the hammer, sight and fire. Or rather, pull the trigger. Almost every single round would require two pulls of the trigger to ignite the primer. First trigger pull would "click". Second would "bang". Previously, shooting ammo that the friend that sold me the gun had loaded, every round went bang first time, every time.

I suppose it's possible the shellholder I bought for the Lee tool might have had enough slop in it (thinner than usual) that it would seat the primer below the head of the case but not actually to the bottom of the primer pocket. That would be inconvenient. But it's easy to measure the thickness of this new shellholder and compare it to others I have.

If that doesn't reveal anything (and even if it does), I will run a half-dozen or so through the RCBS single-stage and use the priming arm to confirm that the primers are fully seated, then take those and another six that are only Lee seated, shoot both groups, and see if it fixes the problem.

Any other ideas? Like, maybe, are Winchester primers hard to ignite?

Thanks in advance.

You have a hammer extender on that buffalo classic? I've heard tell of them slowing the hammer enough that it could cause inconsistent ignition.

Hammer extender?

Hmm - yeah, if you mean a knob that sticks out to the side, since the scope sits right above the hammer.

But it never did this with the ammo that came with it, and the extender has been on it from the beginning (not from the factory, but from when I acquired it).

Over time, the grease on the firing pin will harden. Cold weather makes this worse.
If you haven't taken the firing pin out and cleaned it & where it travels, this can often slow down and soften its strike.
It's a common enough thing that the military has you strip, clean,
and reassemble a rifle bolt dry if you're in cold weather.

About 90-odd percent of the LR primers I've ever used were Winchester.
I do strip out & clean all my bolts every year or two and have never had a issue with them.

Do you think you cleaned the primer pockets deeper?

Ed - I'll try to look in to that. Not sure how at this point, but I'll look.

Chill - pretty sure I didn't. The drill is an old B&D high speed drill I got about 45 years ago. It's strapped down with plumbers tape to a platform so I can power a case trimmer, rather than crank the trimmer by hand. Have it plugged in to a router speed control, slowed way down. The platform is only about 15" long, and fairly thin plywood. If I had pushed hard enough to deepen the hole it should have moved the whole assembly across the work bench, and that didn't happen.

I wouldn't think the primer pocket being a tiny bit too deep would be a issue. If ya really got on with it, maybe.
Having bolts & firing pins taken apart-
I've seen most firing pins will reach way on out there if a primer doesn't stop them.

I'd put my bet on the primers not being deep enough in the cases. I had the same issue last spring with some winchester primers that I thought had gone bad but it turned out that my RCBS hand priming tool was just worn out and not seating them deep enough. Its a slim chance your pocket brush cut the pockets deeper but it is possible but you can measure there depth to find out. The best trick I figured out for cleaning primer pockets is to use a pocket uniformer because its got a depth stop on it so you can't go to deep.

I had a similar situation with an IAB repo Sharps rifle a buddy sold me. About a 40% failure to fire first pull rate. We had several brands of both brass and primes and using primed brass only we tried to find a combo that would work properly. No luck. Then I remembered someone somewhere saying use large pistol primes. I did and they went bang, first time every time. That is what I now use in that rifle and if I somehow get the ammo mixed up with loads made for another rifle, I'm back to the 40% failure.

Should be note that I don't load any of my 45/70's hot, mostly trapdoor level loads. If I need anything faster I have a couple of bolt guns.

Check firing pin protrusion from the bolt face and headspace. A piece of Plasti-Gauge for checking bearing to crankshaft clearance will work. Finally hunt up an original mainspring that might provide a little more steam. Hope you solve the issue.

firing pin is probably broken
with the action open , push on the firing pin, if it stays sticking out, after the spring return, then it is broken, replaced my BIL's the first week he had it

also, make sure there is absolutely no lube on the lock, the gun will jump open and close really fast when shooting, making head scratching why you missed

1Hawkeye has a very good point. If the first strike finishes seating the primer, the second strike makes it go bang. Of course, dirty action, broken firing pin, etc are all good things to eliminate as reasons for the failure. good luck.

First thing I'd check is the firing pin. Easy to do on an H&R with the barrel open, or even remove the barrel while checking. You can lower the hammer and use dial calipers to check off the face of the action to firing pin tip to see how far it protrudes. Might also cock the hammer and push the firing pin down from the rear to double check how far it travels. Use the dial calipers like a depth gauge, not with the caliper ends.
I doubt the Lee primer seating tool is the issue. I've used one for decades and never had any issues seating primers fully. And can't imagine the pockets could be so "cleaned" that they'd get deeper. I rarely clean primer pockets unless I find used brass that's very dirty. I run brass through my wet tumbler after depriming them, and it's always been good enough.

take the firing pin out and clean it and the firing pin tunnel, if it has a return spring see if its broken or kinked.

Well, I went to the range today, but didn't take the gun. I had a more economical thought (i.e. - I'm cheap). I took four sized and deprimed cases, marked them 1-4, and measured depth of primer pocket, primer thickness, how deep the Lee seated them, then how far the press seated two of them. Then ran them all through the gun in the garage, saving live rounds for later.

All primer pockets were measured at the same spot. They were within .001" of the same depth, at .126"-.127" deep.

The four primers were .130", .128", .129" and .130" top to bottom.

All four primers were seated with the Lee Hand Press, and all four were absolutely flush with the base of the shell, not above, not below.

Doing the math, all four primers crushed a little bit as they seated into the pocket, .002" to .003".

The two I ran back through the press seated the primers another .006" and .004" below the rim.

I ran all four through the rifle, and all four went off on the first strike.

All four primers were flush with the rim after firing, so the two that had been deeper seated blew back out to where the frame contacted the breech.

Conclusion: I still don't know what's causing the problem.
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I've not found instructions yet as to how to remove the firing pin.

Just to remove the possibility of not fully seated primers, I'll run my remaining rounds through the press to make sure the primers are as deeply seated as possible.

It will be a while before I'll be able to check anything else. Tax season is upon me, and this year is shaping up to be another very hard one.

I had a problem with my NEF muzzle loader, which is the same gun. Of course, mine uses the little plastic discs and shotshell 209 primers but basic principles are the same. I never understood why, but my gun fired reliably for a few years then all of a sudden started misfiring the majority of the time. Fortunately, I had another identical gun to make measurements and compare. I found the firing pin protrusion was about .034 on the "good" gun, compared to only .017 on the "bad" which was misfiring. Since these guns use a transfer bar I removed the hammer and ground some off the face so that the part of the hammer that contacted the transfer bar could travel further forward so that I got about.034 firing pin protrusion on both guns. The problem was solved. This was a lot of years ago and it's never misfired again.

Regarding primer seating, I used an RCBS hand tool for many years and it was starting to wear out so that I had to constantly adjust it for seating depth. I knew that was causing problems so bought the RCBS Bench tool with the long lever that sticks out over the edge of the loading bench. I highly recommend it for consistency. I've seated close to 4,000 primers since last September and have nothing but good things to say about the feel and performance of the tool.

I had a Buffalo Classic many years ago, and if I recall correctly the firing pin has a cross pin through the block that needs to be tapped out sideways to allow the firing pin and return spring to be removed.

I don't think this is primer related - you might have a marginal firing pin arrangement and certain primers work better than others, but a robust strike should fire anything that's not a dud. Nobody should have to choose one brand over another just to get reliable ignition. Everything should go bang every time...

I have an old El Tigre 44-40 that occasionally required two hammer strikes but I cleaned the firing pin and bolt then lubed everything - problem went away. The hammer strike is a bit light, and I suspect it could do with a new mainspring, although a little bit of maintenance did fix the issue.